THE [O ii]λ3727 LUMINOSITY FUNCTION AND STAR FORMATION RATE AT z ≈ 1.2 IN THE COSMOS 2 SQUARE-DEGREE FIELD AND THE SUBARU DEEP FIELD

We have carried out a wide-field imaging survey for [O ii]λ3727 emitting galaxies at z ≈ 1.2 in the HST COSMOS 2 square degree field using the Suprime-Cam on the Subaru Telescope. The survey covers a sky area of 6700 arcmin2 in the COSMOS field, and a redshift range between 1.17 and 1.20 (∆z = 0.03), corresponding to a survey volume of 5.56×105 Mpc3. We obtain a sample of 3176 [O ii] emitting galaxies with observed emission-line equivalent widths greater than 26 Å. Since our survey tends to sample brighter [O ii] emitting galaxies, we also analyze a sample of fainter [O ii] Based on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan. Astronomical Institute, Graduate School of Science, Tohoku University, Aramaki, Aoba, Sendai 980-8578, Japan Physics Department, Graduate School of Science & Engineering, Ehime University, Bunkyo-cho, Matsuyama 790-8577, Japan National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588, Japan INAF — Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, 50125 Firenze, Italy California Institute of Technology, MC 105-24, 1200 East California Boulevard, Pasadena, CA 91125 Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 Service d’Astrophysique, CEA/Saclay, 91191 Gif-sur-Yvette, France National Radio Astronomy Observatory, P.O. Box 0, Socorro, NM 87801-0387 CNR Instituto di Astrofisica Spaziale e Fisica Cosmica Milano, Milan, Italy Osservatorio Astronomico di Brera, via Brera, Milan, Italy Max Planck Institut fuer Extraterrestrische Physik, D-85478 Garching, Germany Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 Max-Planck-Institut für Astrophysik, D-85748 Garching bei München, Germany Laboratoire d’Astrophysique de Marseille, BP 8, Traverse du Siphon, 13376 Marseille Cedex 12, France Department of Physics, Swiss Federal Institute of Technology (ETH-Zurich), CH-8093 Zurich, Switzerland European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching, Germany Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 Max Planck Institut für Astronomie, Königstuhl 17, Heidelberg, D-69117, Germany Princeton University Observatory, Princeton, NJ 08544 University of Zagreb, Department of Physics, Bijenicka cesta 32, 10000 Zagreb, Croatia American Museum of Natural History CUNY Bronx Community College, New York, NY